Treadle foe use in bail wat signaling



. (No Model.) 2 Sheets-Sheet 1. J. G. DIXON. TREADLE FOR USE IN RAILWAYSIGNALING. No. 527,481.

Patented Oct. 16, 1894.

2 Sheets-Sheet 2.

(No Model.)

I J. G. DIXON.

TREADLE FOR USE IN RAILWAY SIGNALING.

Patented Oct. 16, 1894.

. a; EL

UNITED. ST TES PATENT OFFICE.

JOHN GEORGE DIXON, OF BIRKBY, ENGLAND.

TREADLE FOR ussm RAILWAY SIGNALING.

SPECIFICATION forming part of Letters Patent No. 527,481, dated October16, 1894. Application filed February 20, 1 894- Serial No. 500,890- (Nomodel.) Patented in England December 13, 1898, No. 23,945.

. To all whom it may ooncerni- Beit known that I, J OHN GEORGE DIXON, asubject of the Queen of Great Britain and Ireland, residing at 98 NormanRoad, Birkby, in the county of York, England, have invented certain newand useful Improvements in Treadles forUse in Railway Signaling, (forwhich I have applied for a patent in Great Britain, No. 23,945, datedDecember 13, 1893,) of which the following is a specification.

My mvention relates to an improved form of treadle for actuating anelectrical contact for any purpose in .railway signaling where it isrequired thatthe passage of a train or vehicle shall release, lock oractuate block instruments, signals, bells, indicators or any deviceemployed for the purpose of railway signaling. 1

My inventionconsists in the novel construction and combination of theparts hereinafter fully described and claimed.

In order that my invention may be better understood and more readilycarried into effeet I will describe the drawings hereunto annexed.

Figure 1 is a plan of the treadle showing one form of cylinder or dashpot. Fig. 2 is a section of the dash pot shown in plan in Fig. 1'arranged with a prolonged making contact. Fig. 3 is a section of thelower portion of the same dash pot as illustrated in Figs. 1

I and 2, showing an alternative method of prolonged making contact.

Fig. 4 illustrates a section of the lower portion of the cylinder ordash pot illustrated in Figs. 1 and 2 but at one of its ends below raillevel, and is attached at or near its other end to the transverse levere by means of. the connection 01. The transverse lever e is pivoted atf. The other end of the transverse lever e is coninsulating material.

nected at g to the piston rod h. The piston j is connected to the pistonrod by the nut 'i. k is the cylinder which is open at the top but isclosed and air tight at the bottom Z. m is ing prevents the free passageof air to the upper or open end of the cylinder. Me an outsideprotect-ing shell or case which is connected to the rod h at p. The saidshell or case 0 while acting as a cover also acts as a counter balanceweight. The piston j and cylinder 10 are constructed of anyconvenientconducting material. In a suitable position in the cylinder 71; is fixedan insulator qwhich consists of a plug of ebonite, porcelain or any Ahole is first bored in 7a to receive q, and inserted at or near thecenter of theinsulator q is a conducting stop, pin or spring 1. Torisattached awire s. In electrical contact with It is a wire 15 which isstroke, that is, its normal position, the contact piece 1' is not incontact with the piston j but is situated at such a height that at thecommencement of the upward movement of the piston jelectrical contactwould be completed between j and 'r, and the circuit included in thewires 8 and i will be completed andwill remain completed as long as thepiston j is traveling upward and until it has returned toits normalposition when the circuit becomes broken. It will thus be seen that asthe downward travel of the piston is retarded by meansof the valve m sothe contact that r makes with j (j being already in electricalcommunication with k) will be prolonged correspondingly.

Fig. 8 shows a modified arrangement of prolonged making contact. In thiscase the electrical circuit is completed by means of a springuwhioh isfixed to an insulating piece I) the latter being attached to It. Whenthe piston j rises the inner side of thepiston j comes in contact withthe spring to and remains in contact with 21. until j hasreturned fixedto k by any convenient means. The 130- ,sition of the conducting piece'2" is such that when the piston j is at the bottom of its to the normalposition when the circuit between 8 and t willbe broken.

Fig. 4 shows a form of instantaneous brushes y, 2. These springs y and zare at-' tached to the insulating piece w. In the normal position thepiston j is at the bottom of its cylinder k, then m is in electricalcontact with y and z and consequently the circuit between s and t iscompleted. When the treadle bar a is depressed by the tread of the frontwheel of a passing engine the transverse bar e is tilted so that thepiston rod hand piston j I are moved upward, the contact of 00 with y Iand z isinstantaneously broken and so remains until the return of thepiston to the normal piston and 00 makes contact with y j and .2. Inthis figure the circuit is normally made.

Fig. 5 is a plan showing the treadle, rail,

Fig. 6.

transverse lever and alternative dash pot.

Fig. 6 is a section on line Y-Z' of Fig. 5. :7 In Figs. 5 and 6, theresult is practically the same as that described with reference to Figs.1 to 4 inclusive, the only diflerence bef ing that a .more prolongedcontact is obtained in Fig. 6 and at a certain specified distance I onthe. return stroke of the piston the air is j admitted rapidly into thecylinder and the treadle returns normal immediately. In these figures,a, b, c, d, e, f and gare corresponding parts to those described inFigs. 1 to 4. h is the piston rod; is, the cylinder; j, the piston. k

k is a pipe from the cylinder terminating in a spring valve m. m is thespring. Projecting from h is a tappet h having a ball or other shapedend 72. through which a slot is 1 Operating in this slot is a rod h withmade. adjusting screws k and h atthe ends. A ball valve n is provided atthe upper side of the cending piston, substantially as set forth.

cylinder. The cylinder is inclosed.

The action is as follows z-Normally the rodh with its lower adjustingscrew it is resting upon the upper part of the valve no so that thevalve is normally open. On the operation of the treadle c the transversebar e is raised at the other side of the fulcrum. The piston'rodhandpiston j are moved upward and air is forced out of the valve 12, anddrawn in at the valve m. When the transverse lever and piston have beenraised to a specified distance the termination 71. of the tappet h comesin contact with the adjusting screw it and raises the lower adjustingscrew 72. free of the valve m which closes by the spring at beingallowed to expand. On the return stroke of the piston, the air not beingallowed to escape freely from either of the valves, the return movementis very much prolonged, the

escape being through leakage from the bottom to the top side of thepiston. When the piston has moved down to a pre-determined distance therod h is free to fall so that the nut h presses on the top of the valvem, when air is freely admitted and the piston completes its downwardmotion rapidly.

Although in this figure no electrical contacts are described, it isobvious that those described in Figs. 1 to 4 inclusive are applicable inevery form to the dash pot shown in Other arrangements of valves mightbe made. The chief point, however, of my invention consists in arranginga dash pot substantially as described for the purposes ofmaking'electrical' contacts used in railway signaling.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declarethatwhat I claim is- The combination,with a depressible treadle, and thecounterbalanced and pivoted lever e, of the dash pot cylinder 10,. thepiston sliding therein, the rod h operatively connecting the said leverand piston, the insulated contact piece normally above the piston in thecylinder, and the two conductors connected respectively to the saidcontact piece and cylinder, the circuit being completed by the as- JOHNGEORGE DIXON.

I Witnesses:

WM. RAMSDEN, HAROLD H. RAMSDEN.

